Appropriate epidemiology research design, evaluation, and data management are central to the success of the PO1 Cancer Prevention Research Unit. The functions of the Design, Epidemiology and Evaluation (DEE) core are to provide consultations and services to investigations on all aspects of research design, implementation, evaluation, analysis and reporting. Indeed, this core is referred to as the Design, Epidemiology and Evaluation core to highlight the spectrum of capabilities needed for the PO1-including expertise in biostatistics, epidemiology, social sciences, health economics, and nutrition. The functions of this core will be accomplished by addressing the following specific aims: 1. Aid investigators in refining and implementing an appropriate research design and to finalizing appropriate sampling randomization and stratification procedures. 2. Aid investigators in the conduct of their studies by: (a) addressing issue of subject recruitment and retention, monitoring study progress, and data collection procedures, and (b) developing, initiating and maintaining quality control measures for the conduct of the interventions, particularly related to endpoint monitoring, and ensuring subject safety. 3. Develop appropriate standardized methods for data collection and methods for assessment of common endpoints and mediating conditions among studies, and when appropriate, to enhance collaborative a comparative analyses. Of particular importance is attention to the validity of behavioral and contextual measures in multi-ethnic, economically diverse groups. 4. Develop or select data management systems and computer programs for data entry and editing an to maintain and document all database. 5. Select or develop and implement appropriate analytic techniques for the evaluation of treatment effectiveness, process evaluation and cost- effectiveness.